Teaching co-simulation basics through practice

International audienceCyber-physical system representation is one of the current challenges in Modeling and Simulation. In fact, multi-domain modeling requires new approaches to rigorously deal with it. Co-simulation, one of the approaches, lets modelers use several M&S tools in collaboration. The challenge is to find a way to enable co-simulation use for non-IT experts while being aware of assumptions and limitations involved. This paper deals with co-simulation basic principles teaching through practice. we propose an iterative and modular co-simulation process supported by a DSL-based environment for the MECSYCO co-simulation platform. Through a thermal use case, we are able to introduce co-simulation in a 4 hours tutorial destined to our students. Efficient energy management is one of this century challenges. The current trend to deal with it is to build cyber-physical system (CPS) [Kleissl and Agarwal, 2010]. CPS are physical systems monitored and supervised by one or several computers through a communication networks [Ra-jkumar et al., 2010]. Smart-grids are examples of CPS where the energy network is coupled with a communication network to enable remote monitoring and control. The Modeling and Simulation (M&S) of such systems is one of the current challenges in M&S due to the inter-disciplinary issues they raise. It requests the development of new methods which deal with multi-domain by integrating each expert point of view in the same rigorous and efficient M&S activity. Co-simulation [Gomes et al., 2018] is a way to achieve it

Smart Grids Simulation with MECSYCO

International audienceThese demonstrations are part of the MS4SG project and show the current results of the DEVS-based platform called MECSYCO (Multi-agent Environment for Complex SYstems CO-simulation), formerly named AA4MM (Agents & Artifacts for Multi-Modeling), in the context of smart grids simulation with different use cases based on real scenarios

Future Perspectives of Co-Simulation in the Smart Grid Domain

The recent attention towards research and development in cyber-physical energy systems has introduced the necessity of emerging multi-domain co-simulation tools. Different educational, research and industrial efforts have been set to tackle the co-simulation topic from several perspectives. The majority of previous works has addressed the standardization of models and interfaces for data exchange, automation of simulation, as well as improving performance and accuracy of co-simulation setups. Furthermore, the domains of interest so far have involved communication, control, markets and the environment in addition to physical energy systems. However, the current characteristics and state of co-simulation testbeds need to be re-evaluated for future research demands. These demands vary from new domains of interest, such as human and social behavior models, to new applications of co-simulation, such as holistic prognosis and system planning. This paper aims to formulate these research demands that can then be used as a road map and guideline for future development of co-simulation in cyber-physical energy systems

Multi-agent Multi-Model Simulation of Smart Grids in the MS4SG Project

International audienceThis paper illustrates how the multi-agent approach, or paradigm, can help in the modeling and the simulation of smart grids in the context ofMS4SG (a joint project between LORIA-INRIA and EDF R&D). Smart grids simulations need to integrate together pre-existing and heterogeneous models and their simulation software; for example modeling tools of the power grids, of telecommunication networks, and of the information and decision systems. This paper describes the use of MECSYCO as a valid approach to integrate these heterogeneous models in a multi-agent smart grid simulation platform. Several use cases show the ability of MECSYCO to effectively take into account the requirements of smart grids simulation in MS4SG

Teaching co-simulation basics through practice

International audienceCyber-physical system representation is one of the current challenges in Modeling and Simulation. In fact, multi-domain modeling requires new approaches to rigorously deal with it. Co-simulation, one of the approaches, lets modelers use several M&S tools in collaboration. The challenge is to find a way to enable co-simulation use for non-IT experts while being aware of assumptions and limitations involved. This paper deals with co-simulation basic principles teaching through practice. we propose an iterative and modular co-simulation process supported by a DSL-based environment for the MECSYCO co-simulation platform. Through a thermal use case, we are able to introduce co-simulation in a 4 hours tutorial destined to our students. Efficient energy management is one of this century challenges. The current trend to deal with it is to build cyber-physical system (CPS) [Kleissl and Agarwal, 2010]. CPS are physical systems monitored and supervised by one or several computers through a communication networks [Ra-jkumar et al., 2010]. Smart-grids are examples of CPS where the energy network is coupled with a communication network to enable remote monitoring and control. The Modeling and Simulation (M&S) of such systems is one of the current challenges in M&S due to the inter-disciplinary issues they raise. It requests the development of new methods which deal with multi-domain by integrating each expert point of view in the same rigorous and efficient M&S activity. Co-simulation [Gomes et al., 2018] is a way to achieve it

Designing co-simulation with multi-agent tools: a case study with NetLogo

International audienceMulti-agent approach has demonstrated its benefits for complex system modeling and simulation. This article focuses on how to represent and simulate a system as a set of several interacting simulators, with a focus on the case of multi-agent simulators. This raises a major challenge: multi-agent simulators are not conceived (in general) to be used with other simulators. This article presents a preliminary study about the rigorous integration of multi-agent simulators into a co-simulation platform. The work is grounded on the Net-Logo simulator and the co-simulation platform mecsyco

A component approach for DEVS

International audienceIn this article, we are interested in the reuse of models to allow the design of complex system multi-models. For instance, smart-grid modeling needs models from at least three domains (electrical grid, IP network, control system). Many existing M&S tools are already dedicated to the design of such models. Then, it would be profitable to be able to reuse the models written in these tools to design complex system multi-models. The FMI standard, based on the export and import of models as software components, supports the exchange of models and the co-simulation between ODE and DAE based M&S software. The success of the FMI standard leads us to study the interests of a similar approach based on the DEVS formalism

MECSYCO: a Multi-agent DEVS Wrapping Platform for the Co-simulation of Complex Systems

Most modeling and simulation (M&S) questions about complex systems require to take simultaneously account of several points of view. Phenomena evolving at different scales and at different levels of resolution have to be considered. Moreover, expert skills belonging to different scientific fields are needed. The challenges are then to reconcile these heterogeneous points of view, and to integrate each domain tools (formalisms and simulation software) within the rigorous framework of the M&S process. To answer to this issue, we propose here the specifications of the MECSYCO co-simulation middleware. MECSYCO relies on the universality of the DEVS formalism in order to integrate models written in different formalism. This integration is based on a wrapping strategy in order to make models implemented in different simulation software inter-operable. The middleware performs the co-simulation in a parallel, decentralized and distributable fashion thanks to its modular multi-agent architecture. We detail how MECSYCO perform hybrid co-simulations by integrating in a generic way already implemented continuous models thanks to the FMI standard, the DEV&DESS formalism and the QSS method. The DEVS wrapping of FMI that we propose is not restricted to MECSYCO but can be performed in any DEVS-based platform. We show the modularity and the genericity of our approach through an iterative smart heating system M&S. Compared to other works in the literature, our proposition is generic thanks to the strong foundation of DEVS and the unifying features of the FMI standard, while being fully specified from the concepts to their implementations

Co-simulation of cyber-physical systems using a DEVS wrapping strategy in the MECSYCO middleware

International audienceMost modeling and simulation (M&S) questions about cyber-physical systems (CPS) require expert skills belonging to different scientific fields. The challenges are then to integrate each domain's tools (formalism and simulation software) within the rigorous framework of M&S process. To answer this issue, we give the specifications of the MECSYCO co-simulation middle-ware which enables to interconnect several pre-existing and heterogeneous M&S tools, so they can simulate a whole CPS together. The middleware performs the co-simulation in a parallel, decentralized and distributable fashion thanks to its modular multi-agent architecture. In order to rigorously integrate tools which use different formalisms, the co-simulation engine of MECSYCO is based on DEVS. The central idea of MECSYCO is to use a DEVS wrapping strategy to integrate each tool into the middleware. Thus, heterogeneous tools can be homogeneously co-simulated in the form of a DEVS system. By using DEVS, MECSYCO benefits from the numerous scientific works which have demonstrated the integrative power of this formalism and gives crucial guidelines to rigorously design wrappers. We demonstrate that our discrete framework can integrate a vast amount of continuous M&S tools by wrapping the FMI standard. To this end, we take advantage of DEVS efforts of the literature (namely, the DEV&DESS hybrid formalism and QSS solvers) to design DEVS wrappers for FMU components. As a side-effect, this wrapping is not restricted to MECSYCO but can be applied in any DEVS-based platform. We evaluate MECSYCO with the proof of concept of a smart-heating use-case, where we co-simulate non DEVS-centric M&S tools

Environnement Multi-agent pour la Multi-modélisation et Simulation des Systèmes Complexes

This thesis is focused on the study of complex systems through a modeling and simulation (M&S) process. Most questions about such systems requiere to take simultaneously account of several points of view. Phenomena evolving at different (temporal and spatial) scales and at different levels of resolution (from micro to macro) have to be considered. Moreover, several expert skills belonging to different scientific fields are needed. The challenges are then to reconcile these heterogeneous points of view, and to integrate each domain tools (formalisms and simulation software) within the rigorous framework of the M&S process. In order to solve these issues, we mobilise notions from multi-level modeling, hybrid modeling, parallel simulation and software engineering. Regarding these fields, we study the complementarity of the AA4MM approach and the DEVS formalism into the scope of the model-driven engineering (MDE) approach. Our contribution is twofold. We propose the operational specifications of the MECSYCO co-simulation middleware enabling the parallel simulation of complex systems models in a rigorous and decentralized way. We also define an MDE approach enabling the non-ambiguous description of complex systems models and their automatic implementation in MECSYCO. We show the properties of our approach with several proofs of concept.Ce travail de thèse porte sur l'étude des systèmes complexes par une démarche de modélisation et simulation (M&S). La plupart des questionnements sur ces systèmes nécessitent de prendre en compte plusieurs points de vue simultanément. Il faut alors considérer des phénomènes évoluant à des échelles (temporelles et spatiales) et des niveaux de résolutions (de microscopique à macroscopique) différents. De plus, l'expertise nécessaire pour décrire le système vient en général de plusieurs domaines scientifiques. Les défis sont alors de concilier ces points de vues hétérogènes, et d'intégrer l'existant de chaque domaine (formalismes et logiciels de simulation) tout en restant dans le cadre rigoureux de la démarche de M&S. Pour répondre à ces défis, nous mobilisons à la fois des notions de modélisation multi-niveau (intégration de représentations micro/macro), de modélisation hybride (intégration de formalismes discrets/continus), de simulation parallèle, et d'ingénierie logicielle (interopérabilité logiciel, et ingénierie dirigée par les modèles). Nous nous inscrivons dans la continuité des travaux de M&S existants autour de l'approche AA4MM et du formalisme DEVS. Nous étudions en effet dans cette thèse en quoi ces approches sont complémentaires et permettent, une fois combinées dans une démarche d'Ingénierie Dirigée par les Modèles (IDM), de répondre aux défis de la M&S des systèmes complexes. Notre contribution est double. Nous proposons d'une part les spécifications opérationnelles de l'intergiciel de co-simulation MECSYCO permettant de simuler en parallèle un modèle de manière rigoureuse et complètement décentralisée. D'autre part, nous proposons une approche d'IDM permettant de décrire de manière non-ambiguë des modèles, puis de systématiser leur implémentation dans MECSYCO. Nous évaluons les propriétés de notre approche à travers plusieurs preuves de concept portant sur la M&S du trafic autoroutier et sur la résolution numérique d'un système d'équations différentielles